Dehydrator



Dec. 1o, 1929. A E, YOUNGER 13738550 Y DEHYDRATOR Filed Deo. 13, 1927 5 Sheets-Sheet 1` W /YORNEY Dea-10, 1929. E, L YQUNGER 1,738,550

DEHYDRATOR Filed Dec. 13, 1927 y 3 Sheets-Sheet 2 4Det;` lo, 1929. E, 1 YOUNGER 1,738,550

i DEHYDRATOR v' Filed Dec. 1s. 1927 s sheets-#sheet .3

Il l im IN VEN TOR. (D

ATTORNEY Patented Dea 1o, 1929 ELLARD L. YoUNena, or WOODLAND, cALrORNIA, AssIeNon fro N. r.. YOUNGEN. a

sONs, or' WOODLAND, CALIFORNIA, A corANrNnnsmr oomrosnn or, N. n. YOUNG- im, mmm) r.. YOUNGEN'AND n. .a YONNGEB.

DEHYDRATOR lApplication iled December 13, 1927., Serial No. 239,62.

The invention relates to dehydrators for sively through the dehydrator. p

A general object of the invention is to provide an improved dehydrator of the type shown in Patent Number 1,648,468 which was a issued to me under date of November 8, 1927.

A specific object of the invention is to provide in a dehydrator of the class described, means so regulating and controlling the ap- .,plication of the drying heat to the food that a maximum drying temperature may be used without danger of applying excessive ternperatures Awhich might damage the food.

Another object of the inventionis to -provid'e in a dehydrator of the character described,a tempering compartment for effecting a preliminary heating of vthe food at an adjusted temperature generally below that at which the major part of the drying operation is effected, such compartment being directly included in the air circulating system of the dehydrator.

A 'further object of the invention is to provide in a dehydrator of the class described means facilitating a removal of test specimens of the dried product while the product is disposed in the dehydrator.-

A still further 'object of the invention is to provide in the dehydrator means cooperating with trays carrying the food for confining the air circulation entirely to a predel termined path.

Yet another object of .the invention is to provide inthe dehydrator, improved means for adjustably controlling the inlet of fresh air thereto.

Still another object of' the invention is to provide an improved dehydration process which the apparatus of the present invention is particularly arranged to carry out.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following specication and the accompanying drawings, in which :v l

Flgure 1 is a plan sectional view generally at the ceiling line of a dehydrator embodying I my invention.

Figure 2 is a fragmentary elevation of a sealing means utilized in confining 'the circulated air to a predetermined path.

Figure 3 is a sectional view taken on the Figure 4 is a longitudinal sectional view ,l

taken on the broken line i- 4 in Figure 5.

Figure 5 is a view taken on :the line 5 5.

in Figure 1. Figure 6 is an enlarged fragmentary of a radiator of the dehydrator.v

Figure 7 isa sectional view ktaken on the Ine 7-7- in Figure 6.

View

Figure 8 is an enlarged fragmentary section through a pair of superposed trays in which the food is carriedv for conveyance through the dehydrator.

As vherewith particularly illustrated, the apparatus of the dehydrator is' disposed in a housing structure 1 including side walls 2, a rear wall 3, an open front section 4, a roof 5, and afurnacev pit 6. The structurel is divided longitudinally to provide the pit '6, a blower and radiator compartment 7., and a drying chamber 8, it being noted that a considerable portion of the burner pit Gunderlies'the compartment 7. A furnace 9 is provided in the` pit 6, such furnace being of a usual construction and having a burner 11 for a fluid fuel at its forward end. The heated air and products of combustion are arran ed structed radiator 13in the compartrrient`7 to` j an upper flue portion-14 which discharges above the roof '5. Preferably, and as shown, a suction fan 15`is provided in operative association with the upper flue section 14 for eifecting a positive draft th rough the furnace and radiator.

The drying chamber 8 is provided with a depressedfloor portion-16 extending transversely across the 'housing structure between inlet and outlet doors 17 and 18'respectively. Tracks 19 are provided on the floor portion 16, such tracks extending through bothof the door Openings 17 4and 18 and being arranged to carry trucks 21. As herewith disclosed, two parallel li'nes of tracks are rov1ded whereby two lines of trucks 21 may e simultaneously s ent through the drying chamber. Stacks or tiers 22 of trays 23 Aare arranged to be mounted on the trucks 21, and the trays 23fare formed with cut down front and rear ends 24 whereby passages are defined between the trays and transversely of the tracks. Preferably, and as shown, the tray stacks of successive trucks abut, and such -stacksextend close to the roof, while a whole number' of tray stacks is arranged to closely fit between the inlet and outlet doors 17 and 18 respectively when these doors are closed. Inlthis manner, the stacks of each line of trucks are arranged to cooperate to provide a artition across the drying chamber 8 wherep y air directed thereagainst from either side will be caused to pass between the trays of the stacks and so through the food on the trays.

Means are provided for effecting a continuous circulation of air through the stacks of trays, such means preferably comprising -a 25blower fan 25. The blower 25 is here shown f/ 27 is defined, suc

mounted. upon a horizontal partition or fioor 26 overlying the furnace 9 in spaced relation ,therefrom whereb a fresh air inlet passage il passage connectlng the open front 4 of the structure with the compartment 7. Preferably, the passage 27 is provided with 'means for adjustably controlling the size of the inlet opening thereto, and, as here shown, the means provided comprises `:x5 a damper 28 of the sliding door type, it being noted that the outlet ofthe passage 27 is so related to the streamof air circulated by the blower 25 that such stream will tend to draw in a certain amount of fresh-air through the passage 27, and that the provision of the damper 28 permits an adjusted control of the rate of admission of fresh air to the circulatedk air stream to meet varying requirements as tothe moisture content and temperature of the circulated air, and other factors relating tothe effective'operation of the apparatus.

' The blower 25 is provided with a rearwardly-tiered discharge hood 29 which terminates ff'iiifa vertical plane at the forwardedge ofthe depresse`.d floor portion 16, with the outlet thereof extending from the ceiling 5 to the bottom of the tray stacks 22 and from opposite sides of the central pairs of tray stacks. In this manner. the air stream from the blower 25 primarily passes through the two vcentral stacks 31 of each line thereof. it bener, the` air passing through the stacks 31 is .generally desirable that the circulation flow which lies between the last line of tray stacks and the rear wall 3 is arranged to function as a manifold for distributing the air supplied thereto through the central stacks 31. Prefv erably and as shown, this spaceis divided centrally thereof by a vertical partition 33 to provide chambers 34 and 35, such partition extending longitudinally of the structure from the wall 3 to terminate adjacent the stacks of the rear line thereof. In this manarranged to be divided between the chambers 34 and 35. Preferably, and as shown, the partition -33 is formed to provide cylindrically concave reflecting surfaces 36 and its forward edge lies in the plane of abutment of the stacks 31 of a line thereof. Formed in the rear wall 3 Vadjacent and at opposite sides of the4 partition 33 are openings 37 provided with hinged doors 38 arranged to be fixedI in a plurality of adjusted open positions to permlt thel escape of a predetermined volume of over-humid air, the amount ofair thus escaping being generally complementary to that introduced through the fresh air inlet passage 27 which is controlled byathe damper 28. The settings of the doors 38 and damper 28 are determined by a reading of a hygrodeik 39 mounted in the chamber 34 and arranged to be read through a peephole 41 in the rear wall 3.

It willl now be noted that at least two stacks of traysare arranged to be included in each row thereof on either side of the central stacks 31. As here shown, stacks 42 and 43 are respectively disposed adjacent the inlet and outlet doors 17 and 18 respectively, while stacks 44 are disposed between these stacks. and the central stacks 31. Extendin forwardly from the wall 3 in the planes o abutment of the stacks 42 and'43 with adjacent stacks 44 are partitions 45 and 46 respectively, each partition being provided with an open-.- ing extending generally the full height thereof, and having hinged doors 47 and 48 respectively in the openings. The doors 47 and 48 are hinged at their edges which are closer tothe wall 3 and are arranged to be adjustably disposed across the chambers 34 and respectively in such a manneras to provide an adjustable control of the air flow to the stacks 42 and 43 respectively,- it being of air through these stacks be not as rapid as is that through the stacks 31 and 44. The air flowing forwardly through the stacks 42, 43 and 44, itlwill now be noted is arranged to iiow back to the blower through the passage 49 defined by the space of the compartment 7 about the blower hood 29, a partition 51 being provided across the compartment forwardly of the blower'for confining the air stream, it being noted that the blower is here shown of the type in .which the air is receivedaxially from either Side thereof and is discharged radially outwardly thereair from a blower through .a radiator and then directly ,to the food to be dried. But such practice has, through the possibility of uneven heating and the high temperature primarily given to the drying air, frequently resulted in a scorching or partial cooking of the fruit first reached by the air stream, .and

, an unsatisfactory and unevenly dried product has resulted. In accordance with the present invention, however, such difliculties are avoided by disposing the radiator in the passage49. Accordingly, and as shown, the radiator 13 is formed with side sections 53 connected by inletand outlet manifolds 54 and 55 respectivel at the top and bottom of the radiator, suc manifolds being respectively connected to they lower and upper Hue portions 12 and 14. The radiator sections 53 may be jof any suitable structure for facilitating the radiation of heat therefrom, as here shown, they are formed with a succession of secondary manifolds 56 connected to each other by horizontal pipes 57. In this manner, the incoming air from the passage 27 is "thoroughly mixed with the air heated by the radiators before the heated air is delivered to the central tray stacks 31. To ascertain the condition of the' roduct in the trays of stacks 43, a hand-hof; 58-is preferably provided in the wall 2 adjacentV and forwardly of the stack 43 of the forward line of trays whereby specimens of the product may be taken Awithout opening the dehydrator. Doors' 59 are also preferably providedrin the wall 2 for effecting an entry to the compartment 7 .while the apparatus is filled with the tray stacks.

`Since it is hi hly desirable' that the air stream set up by t e blower 25 be strictly con-L fined to the fixed paths indicated in Figure 1 means are preferably provided for sealin the junctures of the various partitions an walls with the stacks of trays. Accordingly, and as'shown, flaps 61 are provided at the vertical edges of such partitions, such aps being preferably formed of a relatively sti pliable fabric which is disposed to resiliently engage the stacks and at the same time will permit the progression of the stacks through the apparatus. When, as is particularly shown, more than one row of trays is provided for o sts 62 are provided in appropriate position between the rows of trays, such posts being also providedA with the flaps 61.- 1n practice, it has been found desirable to use posts of T-secton for the support of the various aps 61, which flaps may 'each be formedV of aA section of four inch cotton belting.l In' this. manner, a positively controlled and comvplete circulation of the drying air is assured,

and escape of"the.air from the apparatus is minimized. M

It`wil1 now be noted that-when the apparat'us is filled withthe stacks of trays and the heated air is being circulated through the system described, the 'circulation ofy air through the stacks 42 at the inlet doors 17 is arranged to be somewhat less than that through the adjacent stacks 44 whereby the A air in passingthrough these stacks is somewhat cooler than the remainder of the circu- .after advanced to the remainder of the positions across the apparatus. `Preferably, the

draft, door 48 controlling the ow'of air tothe stacks 43 nearest the exit side of the apparatus is also closed somewhat to limit-the circulation rate through these stacks, wherevby the temperature thereat is also somewhat' less than that in the adjacent stacks 44. In practice, it has been found that best results are obtained if-the doors 47 and 48 are so set as to provide an average temperature for the air in the stacks 42 which is about, fifteen Fahrenheit degrees less than is thatof the air through vthe'central stacks 31, while the temperature in the stacks 43 is about seven and a half Fahrenheit degrees less than that of the air lthrough the ,central stacks. The air temperature in the stacks 44 would vbe generally five-degrees cooler than that ofthe central l stacks. In this manner, the stacks are arranged to be exposed to drying air of progressively dierent temperatures as they are moved through the apparatus, with the maxi- .l

mum temperature to which they are subjected an allowable one for-'fthe particular food to be treated. y

Different foods will, ofcourse, h ve maximum allowable dehydrating temperatures, thus for French prunes the maximum is 165 Fahrenheit, witlr-the` other temperatures slightly lower as has been described. It will be noted-that the graduated temperatures of the treatment thus provided, the uniformity of temperature at any point in the :circulated 'air stream, and the uniform and regulated humidity of the air, combine to produce a particularly uniform and superior product.

I claim:

1. In a fruit dehydrator providing a dryer chamber through which a confined stream of air is directed in fixed paths laterally through va line of fruit disposed across the chamber,

vwhich comprises effecting a slower flow of air at said rearward line end than at the in- 5 termediate portions ofthe line.

In testimony whereof, I affix my signature.

ELLARD L. YOUNGER. 

